Explosively actuated cablecutting tool



R. TEQMPLE ET A Filed Oct. 20, 1965 mi NNmUN N. QWQ

EXPLOSIVELY ACTUATED CABLE-CUTTING TOOL Nov. 21,1967 I A OBERT E 4 A TTOfA/E rs.

United States Patent 3,353,267 EXPLOSIVELY ACTUATED CABLE- CUTTING TOOL Robert Temple, Swissvale, and Ernest E. Temple, Murrysville, Pa., assignors to Mine Safety Appliances Company, Pittsburgh, Pa., a corporation of Pennsylvania Filed Oct. 20, 1965, Ser. No. 498,573 8 Claims. (Cl. 30-480) ABSTRACT OF THE DISCLOSURE A cutting tool has a cable-receiving recess in it open at one side. A removable tie bar normally extends across the open side of the recess to keep the frame from bending when a chisel is driven through a cable in the recess by an explosive charge.

It is among the objects of this invention to provide such a cutting tool which can be made light in weight without danger of being bent by the force of the cutting action, and which can be locked on the cable being cut.

In accordance with this invention the cutting tool has a frame provided near one end with a cable-receiving recess that has an open side. A chisel is slidably mounted in the frame and has a front cutting edge that is movable across the recess to cut a cable therein. Mounted in the frame behind the chisel is an explodable device for driving the chisel forward. A removable tie bar normally extends lengthwise of the frame across the open side of the cable recess, the ends of the bar and the adjoining portions of the frame being detac'hably connected together to keep the frame from bending and spreading the open side of the recess farther open when the tool is operated.

The preferred embodiment of the invention is illustrated in the accompanying drawings, in which FIG. 1 is a plan view of our tool;

FIG. 2 is an end view;

FIG. 3 is a longitudinal section of the tool taken on the line III-III of FIG. 1; and

FIG. 4 is a cross section taken on the line IVIV of FIG. 3.

Referring to the drawings, a cable-cutting tool has a metal frame 1 which is hook shape at its front end to form an open sided recess 2 that can receive a chain link or cable that is to be cut by the tool. The hook portion of the frame has a flat top, but the portion behind may be cylindrical and is provided with a longitudinal bore to form a barrel 3. The front end of the barrel opens into the back of recess 2.

Slidably mounted in the barrel is a chisel 5 that 'has a cylindrical rear portion, a thinner rectangular central portion and a tapered front end portion provided with a cutting edge 6. The chisel normally is held in the barrel, with its cutting edge behind the cable recess, by means of a cartridge holding disc 7 clamped against the rear end of the barrel by a cap 8 screwed onto the barrel. The disc is provided with a central opening, in which is mounted the rear end of an explosive cartridge 9 that extends forward into an axial chamber 10 in the chisel. The cartridge is held in place by a small breechblock 12 mounted in the cap and provided with a central opening for a firing pin 13 that is slidably mounted in an axial passage 14 in a rearward extension of the cap. A hollow nut 15 is screwed onto the rear end of the cap, from which a retracting pin 16 attached to the firing pin projects. A ring 17 connected to the rear end of the retracting pin permits the firing pin to be pulled back in the cap and released, whereupon a coil spring I8 around the firing pin will drive the pin forward to detonate the cartridge. The force of the explosion will cause the chisel to be driven ahead at high velocity across the cable recess and through any cable therein and against an anvil 19 of soft metal removably mounted in the front end of the frame.

In the past it has been necessary to make the frame heavy enough, or to reinforce it in such a way as, to prevent the impact of the chisel against the anvil from bending the thin portion of the frame opposite the open side of the recess and thereby spreading the entrance to the recess farther open. It is a feature of this invention that such strengthening or reinforcing of the cutter frame becomes unnecessary, because a removable bar is connected to opposite sides of the recess entrance to tie them together during operation of the tool and thereby prevent bending of the frame.

The tie bar may be a fiat metal bar 21 nearly as wide as the frame, but provided at its opposite ends with integral projections that extend toward the frame and into recesses therein to connect the bar and frame together. For best results, the bar projection 22 at one end of the bar extends across it and a short distance toward the opposite end in a curve, the projection preferably being semicircular. This projection or boss fits in a recess or circular socket 23, with which the frame is provided. The side wall of the socket is undercut and the side wall of the boss slopes outwardly to fit against the socket wall. This hooks the bar onto the frame. The side of the socket at the end of the frame is open so that the boss can he slid into it when the bar is extending laterally away from the frame. The bar then can be swung around until it is parallel to the frame. When the bar extends laterally from the frame, it is prevented from sliding out of position in the socket by means of a stud 24 that has a threaded lower end screwed into the frame at the center of the socket. The stud fits in a recess 25 in the end of the bar and has a head that overlaps the bar. When the stud is screwed down tight, the bar cannot turn in the socket.

The projection at the opposite end of the bar is in the form of a rib 27 curved transversely across the bar and concentric with the semicircular boss. This rib fits into a recess or groove 28 of a corresponding shape in the frame. The side of the groove next to the cable recess is undercut, and the adjoining side of the rib slopes under that wall to hook that end of the bar to the frame.

It will be seen that by swinging the bar laterally away from the entrance to the cable recess, a cable can be in serted in the recess and then locked therein by swinging the bar back across the recess and tightening stud 24. When the tool is fired to cut the cable, there is no danger of its bending opposite to the entrance to the recess, because the omgosite sides of the recess are firmly tied together by the tie ar.

According to the provisions of the patent statutes, we have explained the principle of our invention and have illustrated and described what we now consider to represent its best embodiment. However, we desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

We claim:

1. A cable-cutting tool comprising a frame provided near one end with a cable-receiving recess having an open side, a chisel slidably mounted in the frame and having a front cutting end movable across said recess, means connected with the frame behind said chisel for detonating an explosive charge to drive the chisel forward, and a removable tie bar normally extending lengthwise of said frame across said open side of said recess, means pivotally connecting one end of the bar to the frame for rotation laterally of the frame in a plane substantially parallel to the longitudinal axis of the frame to open said side of the 3 recess, and means detachably connecting the opposite end of the tie bar to the frame to keep the frame from bending and spreading said open side of the recess farther open when the tool is operated.

2. A cable-cutting tool comprising a frame provided near one end with a cable-receiving recess having an open side, a chisel slidably mounted in the frame and having a front cutting end movable across said recess, means connected with the frame behind said chisel for detonating an explosive charge to drive the chisel forward, a tie bar normally extending lengthwise of said frame across said open side of said recess, the frame at one side of the recess being provided with an arcuate socket, said bar having an arcuate boss rotatably mounted in said socket to permit the opposite end of the bar to be swung laterally away from the frame to uncover said open side of the recess, said opposite end of the bar having a longitudinally curved rib extending across it on the same side as said boss and being concentric with the boss, the frame being provided with a curved groove normally receiving said rib so that the bar will keep the frame from bending and spreading said open side of the recess farther open when the tool is operated, and means normally holding the bar in operative position.

3. A cable-cutting tool as defined in claim 2, in which the side walls of said socket and groove next to said recess are undercut, and said boss and rib slope under said walls to hook the bar and frame together.

4. A cable-cutting tool as defined in claim 2, including a fastener in said socket screwed into the frame, the fastener having a head overlapping the adjacent end of said bar and normally pressing tightly against it to hold the bar in place.

5. A cable-cutting tool as defined in claim 2, in which the side wall of said groove next to said recess is undercut, said rib slopes under said wall to hook the bar and frame together, and including a fastener in said socket screwed into the frame and having a head overlapping the adjacent end of the bar and normally engaging it.

6. A cable-cutting tool as defined in claim 1, in which said opposite end of the bar is provided with an integral projection extending toward the frame, and the frame is provided with a recess receiving said projection, said projection and recess forming said detachably connecting means and being separable by said lateral movement of the bar.

7. A cable-cutting tool as defined in claim 6, in which said projection is an arcuate rib extending across the bar, and said recess is an arcuate groove extending across the frame and open its opposite ends for removal of the rib endwise therefrom.

8. A cable-cutting tool as defined in claim 1, in which said frame and tie bar are provided with an interfitting arcuate boss and socket forming said pivotally connecting means.

References Cited UNITED STATES PATENTS 2,003,843 6/1935 Temple. 2,248,642 7/1941 Philips 3O180 2,711,583 6/1955 Raby 30228 3,023,498 3/1962 Temple et al. 3018O OTHELL M. SIMPSON, Primary Examiner.

J. C. PETERS, Assistant Examiner. 

1. A CABLE-CUTTING TOOL COMPRISING A FRAME PROVIDED NEAR ONE END WITH A CABLE-RECEIVING RECESS HAVING AN OPEN SIDE, A CHISEL SLIDABLY MOUNTED IN THE FRAME AND HAVING A FRONT CUTTING END MOVABLE ACROSS SAID RECESS, MEANS CONNECTED WITH THE FRAME BEHIND SAID CHISEL FOR DETONATING AN EXPLOSIVE CHARGE TO DRIVE THE CHISEL FORWARD, AND A RE-MOVABLE TIE BAR NORMALLY EXTENDING LENGTHWISE OF SAID FRAME ACROSS SAID OPEN SIDE OF SAID RECESS, MEANS PIVOTALLY CONNECTING ONE END OF THE BAR TO THE FRAME FOR ROTATION LATERALLY OF THE FRAME IN A PLANE SUBSTANTIALLY PARALLEL TO THE LONGITUDINAL AXIS OF THE FRAME TO OPEN SAID OF THE RECESS, AND MEANS DETACHABLY CONNECTING THE OPPOSITE END OF THE TIE BAR TO THE FRAME TO KEEP THE FRAME FROM BENDING AND SPREADING SAID OPEN SIDE OF THE RECESS FARTHER OPEN WHEN THE TOOL IS OPERATED.. 